Learn to describe collections of objects as sets, and explore simple, fast division techniques from the Vedic method.
A set is a well-defined collection of distinct objects, called elements. Sets are usually named with capital letters and written using curly brackets, with elements separated by commas.
Write the set of the first 5 even numbers.
A = {2, 4, 6, 8, 10}
Is {1, 2, 2, 3} a valid way to write a set?
No, sets don't repeat elements — it should be written as {1, 2, 3}
The Vedic method offers quick mental shortcuts for dividing by numbers close to a power of 10, like 9, 11, or 99, using patterns instead of long division.
Divide 234 by 9 using the pattern that dividing by 9 relates to digit sums.
234 ÷ 9 = 26 (since 234 = 9 × 26)
Why is dividing by 9 often quicker mentally than dividing by 7?
Because 9 is close to 10, so estimating and adjusting is easier than for 7, which has no simple nearby round number
1. Write the set of vowels in the English alphabet.
2. Write the set of the first 4 multiples of 5.
3. Is {red, blue, red, green} a valid set? Rewrite it correctly if not.
4. Divide 189 by 9.
5. Divide 396 by 9.